1. Field of the Invention
The present invention pertains to the art of refrigerated appliances and, more particularly, to a refrigerated appliance having a system for detecting an over-temperature condition in a fresh food or freezer compartment resulting from an interruption of power to the appliance.
2. Discussion of the Prior Art
In general, refrigerated appliances include a freezer compartment for maintaining foodstuffs at or below freezing, and a fresh food compartment for maintaining foodstuffs in a temperature zone below ambient temperature but above freezing temperatures. A typical refrigerator includes an electrically powered refrigeration system having at least a compressor, a condenser, a condenser fan, an evaporator coil, evaporator fan and a plurality of temperature sensors.
In operation, a consumer selects a desired temperature for each of the fresh food and freezer compartments or, in the alternative, a preset temperature value is provided by the manufacturer. Once power is introduced to the appliance, the refrigeration system operates to establish and maintain the selected temperature within each of the fresh food and freezer compartments. During periods of normal use, each of the compartments is accessed several times during a typical day. Each time a compartment door is opened, the temperature inside the compartment rises due to an influx of warmer, ambient air. Sensors arranged within the compartments function to detect any rise in temperature, and in response, the refrigeration system is actuated to return the affected compartment to the selected temperature. Certainly, if the compartment is sealed, the refrigeration system will operate for a short time period in order to re-establish the selected temperature level. However, if the compartment remains open, i.e. the consumer fails to properly close a compartment door, the refrigeration system will operate continuously in order to try to maintain the proper temperature level.
Obviously, with the door open, no matter how efficient the refrigeration system, the temperature of the compartment will not reach the desired level. The warmer, ambient temperature will enter and raise the temperature of the unsealed compartment. Left unchecked, the temperature could rise to a level that would detrimentally affect food stored within the appliance. In addition to problems associated with open appliance doors, compartment temperatures will rise during periods of power interruption.
When power is interrupted to the appliance, the refrigeration system is unable to function. Despite the existence of seals about the appliance which prevent the influx of air to the compartment, over time, ambient air will leak into the appliance. The temperature of the compartment will rise, and if power is interrupted for a prolonged period, food within the appliance will spoil. When power is returned, the refrigeration system will operate normally, pulling down the compartment temperature to the selected level. Left unaware, the consumer may inadvertently consume spoiled food items.
Therefore, based on the above, there exists a need in the art of refrigerators for a power interrupt system that provides an indication to a consumer of an over-temperature condition developed during periods of power interruption. Specifically, to a power interrupt system which will display to the consumer the highest temperature reached during the period of the power interruption so that an informed decision can be made as to the likelihood that the food stored within the appliance has spoiled.
The present invention is directed to an power interrupt system for a refrigerated appliance. More particularly, the power interrupt system is provided to detect an out-of-range temperature condition for fresh food and freezer compartments of the refrigerated appliance after the occurrence of a power interruption. In accordance with one form of the present invention, the power interrupt system includes a control unit having a temperature selector element, a central processor including a memory storage module, and a plurality of temperature sensors arranged about the appliance. The temperature sensors, in combination with the control unit, function to monitor fresh food and freezer compartment temperatures and activate a refrigeration system upon a sensed cooling demand. In operation, the power interrupt system compares sensed temperature values with stored temperature variables. If, after a power interruption, the sensed temperatures exceed the stored temperature variables by a predetermined amount, a power interrupt or over-temperature flag is triggered.
In accordance with another preferred form of the invention, a first variable set, defined by an interrupt temperature for each of the fresh food and freezer compartments, is stored in the memory module. Preferably, the interrupt temperature represents the lowest possible temperature setting for the respective refrigerator compartment. A second variable set, defined by a current set point temperature for each compartment, is also stored in the memory module. Upon activation, after sensing a power interruption and subsequent re-initialization of power to the appliance, the control unit begins monitoring the post power interrupt temperatures for the compartments. Each time the control unit scans post power interrupt temperatures for the compartments, the values obtained are compared to the values stored in the first and second variable sets. If the current post power interrupt temperature exceed the corresponding value stored in the first or second variable sets, an out of temperature range flag is triggered and a visual indication to this effect is displayed to the consumer.
In the most preferred form of the invention, the refrigerated appliance includes an exteriorly mounted control panel having an alpha-numeric display. Once the out-of-range temperature flag is triggered, an alarm indicating the over temperature condition is activated. In the most preferred form, the display flashes the out-of-range temperature value for a particular compartment intermittently with the current compartment temperature value. More specifically, the display is continuously updated such that the highest temperature value realized by the compartment is displayed to the consumer. In addition to the out-of-range temperatures, the display will provide the consumer with an indication that a power interruption has occurred. This can take the form of a flashing display, an audible signal, or a combination thereof. In this manner, the consumer can decide if the compartment temperature was elevated to a point that would necessarily result in spoilage to the food stored within the compartment. Preferably, the display will continue to flash the alarm until a reset button is manipulated, thus ensuring that the consumer was made aware of the alarm condition.
Additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of a preferred embodiment when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.